Suspending device for overhead electric conductors



(No Model.)

B. THOMSON. SUSPENDING DEVICE FOR OVERHEAD ELECTRIC 0ONDUOTOR$. No.435,870. Pa tented Sept. 2, 1890.

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ELI lIU THOMSON, OF LYNN, MASSACHUSETTS.

SUSPENDING DEVlCE FOR OVERHEAD ELECTRIC COND UCTORS.

SPECIFICATION forming part of Letters Patent No. 435,870, datedSeptember 2, 1890.

Application filed June 20,1890. Serial No. 356,115. (No model.)

To all whom it may concern:

Be it known that l, ELIHU THOMSON, a citizen of the United States, and aresident of Lynn, in the county of Essex and State of Massachusetts,have in vented certain new and useful Improvements in Suspending Devicesfor Overhead Electric Conductors, of which the following is aspecification.

My present invention relates to the line con struction of an electricrailway in which the conductor is suspended above the roadway byspan-wires or other of the well-known means for this purpose; and itsobjects are to provide a high degree of insulation for the trollcy-wireand a supporting insulator-hanger, simple in its construction yet highlyeffective, which is alike durable and easily replaceable.

With these objects in view my invention consists, in general, of asubspan or sway wire, preferably insulated, which is attached at its endsto the customary cross-wire of an electric-railway, and from which thetrolley-wire is suspended, and, secondly, in a special construction ofinsulator, all as pointed out in the claims hereinafter made.

The invention will be understood by reference to the accompanyingdrawings, in which Figures 1 and '3 are perspective views showing,respectively, 1n cans forsupporting a single and two trolley-wires abovethe street-surface. Fig. 3 is a vertical sectional view of theinsulator-hanger. Fig. :1: is a plan view of the same; and Figs. 5 and Gare detailed views, the former showing a modification of the arrangementin Fig. 5.

In Fig. 1, 1 P represent conventionally poles or other supports placedon opposite sides of the street, from which is strung a cross or spanwire S, transverse to the roadwayand at any desired distance above thestreet-surface. As will be seen, this span-wire extends straight acrossfrom one point of attachment to the other, and is preferably unbrokenbetween the points where it leaves the insulators.

In case a single trolley-wire is to be used, as represented in Fig. 1, Imake use of a supplemental wire S, forming a loop depending below thespan-wire. This wire is clamped to the cross-wire at two points C O atsome distance from the center, and carries at its middle portion theinsulator-hanger, which in turn supports the trolley-wire. \Vhile theloop of this one may be formed of bare wire, I preferably make it ofinsulated wireas, for instance, one covered with a close braid andthoroughly water-proof, two or three layers being desirable. This givespractically an insulating span or loop between the points 0 0, uponwhich the insulator I is hung.

\Vhen two trolley-wires are support-ed from the same cross-wire, thearrangementis modified, as in Fig. 2, where T T are the two trolleylinesand I I are the insulator-hangers carried on the loop-wire S, which isclamped to the main span-wire at the points 0 O, as before. It will ofcourse be understood that in supporting a long wire this structure isduplicated at successive points along the line.

\Vhile the hanger I may be made in a number of ways, I prefer thefollowing special construction, (shown in Figs. 3, 4, 5, and 6,) whichis one capable of being attached to the loop- -wire S. In Fig. 3, Srepresents a loop wire with a heavy braid covering B, treated so as tobe water-proof. I prefer also to again cover the wire at the point whereit is desired to attach the hanger by a lead tube L, which extends for ashort distance each side of the hanger. This tube serves the purpose ofpreventing abrasion of the braid, while no leakage of current can occur,as it extends for a considerable distance on each side of the hanger I,so that the loop-wire S is at all times dead. The insulation of the wireS is, however, a secondary insulation, since the main insulation is inthe hanger l itself, which is constructed as follows: A metallic clip Mis provided having 011 each side an offset arm D, curved or bent into ahook at its outer end. The transverse wire is passed around this clipjust above the bead Gand then bent so as to pass through the hooks D D,as shown in Fig. 4-. Through the body of M there is a vertical bore forthe reception of a hollow cylinder or thimble of insulatin g material,having a stem projecting up into the bore in the clip M and abell-shaped portion N for shedding water. Through this spool passes ametal screw or bolt provided with a head H, slightly wider than the borein the clip, and a screw-threaded portionV. The head His embedded in acap of insulating material, which keeps it out of contact with the metalclip. In this way not only is the head of the bolt protected fromleakage, but it is also impos sible for it to be pulled down through theclip, thus detaching the trolley-wire from the span-wire. 1

Secured to the insnlatoris the part K, acting as a nut for thescrew-thread B, to which is attached by a bolt or rivet the ear E,suspending the trolley-wire. Fig. 6 shows these parts more in detail,wherein T is the trolleywire secured to the lower parts of the ear E,which is pivoted between the cheeks project ing from the nut K, andtherebyis permitted a certain amount of swinging motion. A rubber washeris inserted between the insulating-cap around the head H and theinsulator-stem, so that in securing these parts together the rubberwasher (marked IV) is compressed, making a tight joint and keeping outall moisture. In some cases a metallic cover (shown in dotted lines) isplaced over the cap and secured by screws at its lower edge, which passunder a flange upon the upper end of the clip M. The insulating materialmay be porcelain or hard rubber, or of various compositions which arestrong, resist compres sion, and are water-proof.

Fig. 5 shows a modification, where M is, as W before,a perforated metalclip which receives the insulator and boltll. The head of the bolt issunk in a sort of cup R, the sides of which project upward and retain inposition a body of plastic ma erial Q-such as soft pitchabove the headof the bolt, thereby making it practically water-proof.

In order to make the joint between the portions of the insulatingmaterial tight and at the same time elastic, as respects the metal clipM, I prefer to bevel-the outside edges of the piece V and clip M and toinsert rubber rings W' W, which are a little too large for the space,and therefore are compressed when the parts are put together. I thussecure elasticity and guard against the entrance of moisture, whichmight form a leak, by connecting the inner bolt H with the clip M.

It will be understood that the insulatorhanger described may be usedwith the ordinary span-wire, such as S, omitting the depending loop S';but in such case the total amount of insulation is not so great. In thesame manner the wire S mighthave attached to it other insulating devicesthan the hanger described; but I find that the two cooperate in the bestway to secure a thorough insulation and to make a complete structure.

It is a matter of very little diiiiculty, as will be seen, to adjust theposition of the insulator-hanger or to put a new one in place.

Furthermore, as the trolley-wire expands and pending edges of thewater-shed N" to reach the metal M; and even if the circuit is completedthus far there is still a long distance to be traversed over theexterior insulation,

,due'to the braid B, before the main span- .wire S is reached;

vmental insulated wire attached thereto and forming a depending loop, ofan insulatorhanger attached to the supplemental-wire and sustaining theline-conductor, as described.

3. The combination, in an electric railway, with a transverse insulatedwire, of a protecting-casing, as L, an insulator-hanger attached to. thewire at a point protected by the casing, and a line-conductor supportedby the hanger. V

4. The combination, with a span-wire of an electric railway, of thesupplementalinsulated wire attached at its ends to the spanwire andforming a swinging loop below the same, the protecting-casing, as L, andthe insulator-hanger attached to the loop over the casing and comprisinga metal clip, and an insulator intermediate between the clip and thetrolley-wire, as described.

5. The combination, in an electric railway, of the insulator, thesurrounding'clip around which the supporting transverse wire' is passed,the ear for sustaining the line-conductor, and the fastening screw orboltpassing down through the insulator and having its head. protected byinsulating material, as set forth.

6. The combination of the metal clip having a central opening andtheinsulator having a stem projecting into said opening, with the bolthaving a vertical bearing upon the through the insulator and securingthe dif- [O ferent parts of the hanger together, as described.

Signed at Lynn, Massachusetts, June 16,

ELIHU THOMSON. Witnesses:

JOHN W. GIBBONEY, ALBERT L. ROHRER.

